Steam engine piston



Aug, 14, 1934. v, w, ELLET STEAM ENGINE PISTON Filed Feb. 16, 1935 figl 2 Sheets-Sheet l f w WL Invewi'or-a- Vi'cibr WE'ZZE Aug. 141-, 1934. v W. -r 1,970,132

STEAM ENGINE PISTON Filed Feb. 16, 1933 2 Sheets-Sheet 2 Patented Aug. 14, 1934 stares PATENT FFiifE Spiller Manufacturing Corporation,

Boston,

Mass, a corporation of Massachusetts Application February 16, 1933, Serial No. 657,034

2 Claims.

This invention relates to steam engine pistons and the object is to provide a construction thereof having certain advantages in use as will appear as the description proceeds.

My invention may be well understood by reference to the following description taken in connection with the accompanying drawings show ing by of example a single embodiment of the invention and in which:--

1 is section through the cylinder, steam chest and steam pipe of a locomotive;

Fig. 2 is a perspective of the piston bull ring part broken away;

Fig. 3 is a cross section thereof; and

4 is a fragmentary view thereof; part section and part side elevation.

My invention finds a particular application to pistons for steam engines of the horizontal type as are used in locomotive as herein illustrated way of example. Thus, referring to Fig. l, I have shown the cylinder 5 of the locomotive with the adjacent steam chest 7 to which steam is supplied through steam pipe 9. Oil may be delivered to the steam pipe 9 through the nozzle 11 in customary manner to be distributed by the steam to the interior of the cylinder. An important feature of invention is facilitating the distri utio of such oil to the cylinder walls.

The piston herein shown as an example of my invention may embody the outer portion or bull g 13 pro ably of cast iron and provided with interior cen ral rib 15 by means of which it may be riveted to the central web 17 carried by th piston rod 19. As best seen in Figs. 1 and 2, the lower portion of the bull ring at 21 may be of relative y width providing a so-called shoe or tlalli. Piston ring grooves 23 are pro The feaconstruction so far described are not in themselves new.

I ng now more particularly to Figs. 2 and 4, I provide the lower portion of the bull ring, where it is enlarged to provide the shoe, with recesses 25 located between the two piston ring grooves 23 and which are preferably enlarged and circun'ierentially extended as indicated at 2'? inward y of the hearing face of the shoe. The central portion of the shoe section is thus substantially cut away or cored out while strength therefor is provided the walls 29 intervening between the extensions 27 of the recesses and the bearing surface of the shoe is not unduly diminished in ar a by the relatively small recesses 25. This construction lightens the gross weight of the bull ring, thereby reducing the pressure per square inch on the wearing face, and makes for more uniform metal sections throughout the shoe part of the bull ring, thereby producing a more uniform material with greater resistance to Wear.

Drilled openings 29 may extend from the inner face of the bull ring to the pockets provided by the recesses 25 and their extensions 2'? and I have herein shown them as extending alternately from successive pockets to opposite sides of the rib l5 and thus to opposite faces of the piston considered as a whole. These passages are unobstructed and the steam from the interior of the cylinder may enter freely therein. As the openings 25, however, open to the space between the piston rings in the groove 23, there is no com munication between opposite sides of the piston. The steam does not press on the piston rings in such a manner as to cause them to bind unduly against the cylinder walls. On the contrary the entrance of the steam pressure reacts to some extent against the lower cylinder wall and tends to balance the dead weight of the piston by tending to lift the same by such pressure.

The steam which enters the pockets carries with it a certain amount of oil in suspension of the piston and the corresponding face of the cylinder between the piston rings.

I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive; reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

I claim:

1. A piston head for a piston of a steam engine of the horizontal type comprising a web and a circumferential bull ring, the lower portion of said bull ring being laterally extended to provide a bearing surface of relatively great width as compared with the other portions of the ring, said bull ring in the arc thereof corresponding to the location of said extended portion having a series of circumferentially extended chambers formed therein inwardly of the outer face thereof, the chambers having relatively restricted openings therefrom, whereby more nearly uniform sections of metal are provided throughout the circumference of the bull ring while maintaining a large wearing area at the lower portion thereof.

2. A piston head for a piston of a steam engine of the horizontal type comprising a web anda circumferential bull ring, the lower portion of said bull ring being laterally extended to provide a bearing surface of relatively great width as compared with the other portions of the ring, there being piston ring grooves encircling the ring, said bull ring in the arc thereof corresponding to the location of said extended portion having a series of circumferentially extended chambers formed therein inwardly of the outer face thereof, the chambers having relatively re stricted openings leading therefrom to the space between the grooves, there being passages extending from the inner portions of said chambers to the inner face of the extended portion to receive by gravity oil precipitated from the steam on the web of the head.

VICTOR W. ELLET. 

